Method and apparatus for pressure die-casting



E. msnaneowmn' METHOD AND APPARATUS'FOR PRESSURE DIE CASTING.

' APPLICATION fll ED MAY I4; 19" 1,377,226. a ed M y 10, 1921.

mun/Ton Ear-Z Ji- .S'hefband WITNESS UNITED STATES EARL n. SHERBONDY,

METHOD AND APPARATUS r PATENT OFFICE.

or cLEvELmvn; 01110. I i on PRESSURE mn-ces'rme.

1,377,226. 7 Application filed May 14,

T 0 all whom it may concern:

Be it known that I, EARL H. SHERBONDY, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvementsin Methods of and Apparatus for vPressure Die-Casting, of which the followingis a specification.

This invention relates to a method of and apparatus for casting any kind of molten material, such as "ordinary metals, as well as other materials which .are susceptible of being cast, such as bakelite. More particularly the invention comprises a method and means of pressure die casting, that is to say; one in which the metal is projected into and held in the die under pressure, until it is sufficiently cool to be removed.

The particular object of the invention is to utilize centrifugal force as the force which presses the molten mass into the die and holds it there until cool. T0 this end the 7 die is adapted to be rotated at high speed, and the molten mass is fed to said die, so that it is. practically instantaneously projected into the die, and held there under a pressure dependent upon the specificgrav ityof the metal that is being cast, and the speed of rotation of the die.

This method'of casting-presents this advantage :Since the mass of molten material is much heavierthan any small bubbles of air or-other gas that may be caught-by; the. molten mass on its way tothe die,- or which may be present in the molten mass, the centrifugal force will carry this heavier metal as far away from the axis of rotat on as possible, which will result in the relatlve movement of all of these small bubbles of gas inwardly, thus givinga dense castlng.

Another object of the invention is to provide suitable cooling means for the die, such cooling being necessary in order to prevent the die from becoming so hot that the molten, mass being cast therein will fuse thereto.

Another object of the invention is to rovide means to cause forced circulation o the cooling medium over. the outside face of the die, in order to provide a rehable and 'eflicient cooling action. a I;

Other objects and advantages Wlll appear as the description proceeds.

, Referring now to the drawings which are' diagrammatic, Figure 1 isa vertlcal sec- .tional view of the apparatus embodying'my Specification of Letters Patent.

Patented May 10, 1921. 191a. seriai No. 234,5e1.

invention, and Fig. 2 is a Section on the line 2-2 of Fig. 1.

In Fig. 1, the upper and lower die-forming elements'l and 2 cooperate to definea dle space 3, which space 3 is intended to be filled with the metal that is being cast to form the finished casting, and is accordingly cut from the'die-forming elements 1.

and 2 to define a Space of the desired shape.

These elements 1 and 2 are circular in shape,andv are intended to be operated at a high rate of speed. The box-like casing 4, 7

provided with a top 5, is arrangedaround the die, the top 5 being formed with a suitable ing 6, and packing gland 7, for the proper mounting of' the upper part of the element 1, While the casing 4 is provided with an aperture 8 for the passage of the shaft 9 of the die-forming-element 2. -The shaft portion 9'may be integral with part 2. A' flange 9"," integral with the shaft 9, and a packing gland 10 cooperate withthe shaft 9 to provide a tight joint before the shaft 9 passes out of the box 4. Shaft 9. is mounted in a suitable step bearing 11, and isrotated as the pulleyand belt 12.

Theimolten material is fed to the die 1 through a vertically arranged funnel ele-' ment 13, which is held stationary in a suitable support 14, and passes inwardly through. the packing gland 7, and throughthe upper part 15 of the die-forming element 1, and opens into the 'space16 between the die-forming elements 1 and 2. The lower die-forming element 2 may b provided with a conical projection .17, arranged concentricall with respect to the funnel element 13. he funnel element13 may be lined with-a refractory lining 13'. It should be noted-that the space 16 is in direct communication with the. severalspaces 3 forming the mold;

The parts 1 and '2 of the die may be offset as at18,- toaid in proper positionln of the two. elements, and may be further eld together' by screws or bolts 19, and a ring 20. Q It is necessary to keep the elements 1 and.

2 comparatively cool in order to prevent the molten mass that-is being cast from; fusing therewith. To this end the box"4 is filled with some cooling medium, such as air,

water,-oil orv molten lead, for example,-depending upon the temperature at which it is desired to keep the die. In orderto as- 80 at high speed by any suitable means, such t the method may be modified and carried out sure intimate contact between this cooling medium and the outside surfaces of the die,

the cooling; {medium may be kept under.

fairly-high pressure by a pump 21. In 5 orderfto-induce a forced circulation-of'the cooling medium over the outside surfaces of the die, such Outside surfaces may be provided withflthe curvedribs 22, which are analogous to the. blades of a centrifugal pump. These blades 22 will pick up the cooling medium from near theaxis of rotation of the die, andproject it outwardly by centrifugalforce, so'causing a forced circulation'of the cooling medium and a more i5 reliable cooling effect; In order to further .enhance'this cooling effect, annular disk- 1' like elements23, supported by studs. 24

mountedon the. casing elements 4 and -5, are positioned-slightly spaced from the outside surfaces of, the-die, and substani 25 15 and"9 lofi the die. The disk-like elements the cooling element over the 23 accordingly-define adefinite channel for the passageo v outside surfacesfof thei'die, the described ribs22 forcing the .coolin medium outwardly, resulting in more eing taken in through-the opening 23', acontinuous, circulation.

The. funnel 13 lSPOSltlOIlBd. within the portion15 of the element 1, so as to. be

and so providing 5 slightlyspaced therefrom to leave a space 15 for the escape of gas from the space 16.

The operation of the device willnow be apparent. The box 4 is filled with the desired cooling medium at the proper tempera- 40 ture, the die then speeded up to a high'rate of speed, and the molten metal poured in through the funnel element 13; the metal passes into the space 16, and is immediately and powerfully thrown by centrifugal force into the mold 3, where the centrifugal force will hold it as long as the rotation is kept up. Due tothe high specific gravity of the molten mass, relative to any small bubbles of gas which may be present, the molten 50. mass will be thrown to the outside, and the bubbles :of gas-forced to the inside, thereby giving a dense casting, free from bubbles.

When the arts are sufficiently cool, the

parts are disassembled, the die taken apart and the castings removed.

It shouldbe understood that this invention is applicable to any form of casting, not v only of metal, but of other materials that may be susceptible of casting,-such as ba- 50 kelite. r 1

While I have shown apossible embodi *'ment of; my,invention, and'have suggested possible steps in carrying it out, it should be understood that both the apparatus and in other ways, as defined within the scope of the appended claims.

' I claim- LA casting apparatus,-comprising. dieforming means adapted to rotate at high v speed, means for feeding a molten mass to said die-forming means, means to immerse said die-forming means in a cooling medium, said die-forming means being provided withmeans on the outside thereof to pick up said cooling medium and cause a forced circulation thereof. I 2. The combination as claimed in claim 1, in combination with means positioned in the cooling medium to define a path for the cirg0 culation of saidcooling medium over the outside of said die-forming means.

3. A casting apparatus, comprising dieforming'means adapted to rotate at .high

speed, means for feeding a'molten mass to 35 said dle-formlng means, means .to lmmerse said die-forming means in a cooling me-' dium, and means positioned in the. cooling medium to define a path for the circulation of said cooling medium over the outside of saiddie-forming means; a a 4'. In a centrifugal casting machine, the

; combination of a mold structure,supporting means for mounting the mold structure for rotation about a vertical axis, the ,mold 5 structure being so shaped and arranged as to provide, substantially concentric with the axis, an annular chamber formed by two converging walls, with the open sideof the chamber directed toward saidv axis, and means for confining a body of cooling liquid in contact with the exterior of the mold structure at all times.

5. In a centrifugal casting machine, the combination of a mold structure, supporting means for mounting the mold structure for rotation about a vertical axis, the mold structure being so shaped and arranged as to provide, substantially concentric with the axis, an annular chamber formed by two converging walls, with the open side of the chamber directed toward said axis, the upper surface of said mold structure within the bounds of the annular chamber being formed and arranged as an initialreceptor, and centrifugal projector for molten metal, and means for confining a body of cooling liquid in contact with the exterior of the .mold structure at all'times.

6. In a centrifugal casting machine, the

combination of a mold structure, supporting means for mounting the mold structure for rotation about a vertical axis, the mold structure being so shaped and arranged as to provide, substantially concentric with the axis, an annular chamberformed by two converging walls, with the open side of the a chamber directed toward said axis, the up per surface of said mold structure within the boundsof the annular chamber being formed and arranged as an initial receptor, and centrifugal projector for molten metal, said receptor being formed as an upstanding protuberance substantially identical in all axial sections, and means for confining a body of cooling liquid in contact with the exterior of the mold structure at all times;

7. A casting apparatus, comprising dieforming means adapted to rotate at high 10 speed about a vertical axis, means for feeding molten metal to said die-forming means, a chamber around said die-forming means adapted to contain a cooling medium in contact with said die-forming means, said dieforming means being so shaped on the outer surface thereof as to increase the cooling action of the medium employed. 7 t

In testimony whereof I afiix my signature.

- EARL H..SHERB'ONDY. 

